Sewing-machine



C. E. FRANCIS. SEWING MACHINE. APPLICATION FILED JAN. 19. 1918.

Patented July 13, 1920.

2 SHEETSSHEET 1.

2; M, Jaw, mm W C. E. FRANCIS.

SEWING MACHINE.

ARPLICAHON FILED JAN.19, 1918.

1,346,120. Patented July 13,1920.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

CHARLES EDWARD FRANCIS, OF WESTMINSTER, LONDGN, ENGLAND, ASSIGNOR TO VIGKEBS LIMITED, OF WESTMINSTER, ENGLAND.

SEWING-MACHINE.

Specification of Letters Patent.

Patented July 13, 1920.

Application filed January 19, 1918. Serial No. 212,608.

T 0 (M whom it may concern:

Be it known that 1, CHARLES EDWARD Francis, a subject of the King of Great Britain, residing at Vickers House, Broadway, Westminster in the county of London, England, have invented certain new and useful Improvements in or Relating to Sewing- Machines, of which the following is a specification. i

This invention relates to the stitch regulating and reversing mechanism of sewing machines and the main object thereof is to provide an improved device for use in the adjustment of the'fecd and consequently of the stitch, so that on reversal of the feed or stitch the same rate or length shall be retained or the work moved at a rate having some predetermined ratio to its rate ofmovement in the other direction.

The usual stitch regulating mechanism comprises a forked rod or member which is reciprocated laterally by an eccentric or cam working in the fork and which is also capable of longitudinal or vertical reciproca' tion. This member has pivoted to it a link which at its other end is pivoted to the end of a lever (hereinafter referred to as the control lever) which is fulcrumed on a fixed axis. The longitudinal or vertical reciprocation of the forked member is obtained by the lateral movement causing the link to turn in an are on its axis on the said lever the restraint or control in movement thus provided causing the said member to reciprocate longitudinally or vertically more or less. The extent of this longitudinal or vertical reciprocation depends upon the position of the control lever and consequently the axis of the link connected to it and the parts are so arranged that when the said lever is moved over a neutral position the vertical reciprocation of the forked member is reversed so reversing the feed and stitch! In another common form of stitch regulatingmechanism the aforesaid forked membcr carries a roller which engages in a slot or recess in a pivoted block that may be inclined more or less on either side of a neutral position to cause, vary and reverse the longitudinal or vertical reciprocation of the said member.

In mechanisms such as those aforesaid the movement-of the control lever or the aforewhich controls the rate and direction of the feed (hereinafter referred to as the control member) has been adjustably limited by a stop co-acting with an abutment member relative angular movement being provided for between the said stop and abutment member. According to the said invention the operative face of the abutment member is so shaped that it is of a projecting form on the outer side of an imaginary straight line from one of its operative extremities to the other, in distinction to the said face being concave or of an angularly recessed shape or flat. For example according to the said invention, the aforesaid operative face may be convex or of angularly projecting form but it is preferably convex. The aforesaid abutment member mayeither be carried by, and thus turn angularly with the control member or it may be in a fixed position, and the aforesaid stop carried by and turn angularly with the control member. The distance at'any time between the said stop and the abutment member limits the movement of the control member on either side of its neutral position the degree of limitation being dependent on the said distance, maximum movement of the control lever being permitted when the operative face of the stop is in its farthest position from the axis on which the abutment member turns.

Another feature of the said invention is that the said stop has a helical groove in which engages a member projecting from the bearing for the stop so that when the stop is rotated axial movement is imparted to'it. This arrangement is in distinction to the stop being provided with a screw thread engaging with a screw thread in the stop bearing and has advantages over such an arrangement. The helical groove aforesaid may be of definite limits corresponding to the desired length of travel of the stop whereby the parts may be assembled without the need of any initial axial adjustment of the stop in its bearing or adjustment relatively to an index as is necessary when the stop is engaged in its hearing by ordinary screw threads which are of indefinite length, that is, of a length having no limitation relatively to the desired limits of travel j of the stop. According to another feature of the saidinvention the aforesaid member engaging with the said helical groove in the stop is a screw which may be turned to have merely a working fit in the groove when the stop is to be adjusted or turned down to bear on the stop and secure it in adjusted position. An index of positionsof the stop is preferably provided and according to another feature of the invention this index is helically arranged with a pitch similar to that of the V aforesaid helical groove.

In order that the nature-of the said invention and themanner in which it may be practisedshall be clearly understood, the said invention is hereinafter particularly described with reference to the accompanying drawings which illustrate preferred embodiments of the said invention.

Figures 1 to 5 of the said drawings illustrate the preferred embodiment of the inven-- tion in stitch regulating and reversmg mechanism of the kind first hereinbefor e described, that is, mechanism comprising a forked reciprocatory member pivoted by tion Fig. 1, showing the aforesaid mechan sm in edge view looking from-the left hand ofFig.1. 4

Fig. 4' is a fragmentary hor 1zontal section taken on the line A Fig. 2, and Fig. 5 is a fragmentary section taken on the line B BFig. 1.

Figure dis a sectional view illustrating an arrangement in which the abutment member is fixed and the axially adjustable stop is carried by and turns with the. control lever. j Fig. 7 is a vertical section taken through the bracket arm of a machine illustrating an embodiment of the said invention in stitch regulating and reversing mechanism of the kind in which there is employed a slotted or'recessed block as hereinbefore described.

Fig. 8 is a fragmentary horizontal section taken through'a part of the bracket arm immediately above the part in which the aforesaid stop works, illustrating one form of index or indicating means hereinbefore referred to.

Figs. 9 and 10 are diagrammaticviews illustrating modified forms of the operative face of the aforesaid abutment member.

In the following description the parts ofthe said drawings are referred to by the lette'rs'and numerals marked thereon the same letters and numerals indicating the same or equivalent parts in all the figures of the drawings.

knob e against the said faces.

the sald control lover e is the aforesaid abut-' The arrangements illustrated in Figs. 1 to 5 will be first described.

a is the aforesaid forked reciprocatory is rotatably mounted at e on a pin secured inthe rear wallv ofthe bracket arm. These parts are usual and the vertical reciprocation of the member a is caused by the lat eral reciprocations thereof and the link connection of the member a with the control lever e. The extent of the vertical recipro cationsdepends upon the distance between the axis of the connection at e and an imaginary line passing through the axis of the shaft on which the cam Z) is mounted, and the axis at 6 so that by turningthe control lever e the length of the vertical reciprocationsv of the member a may be varied and consequently the length of stitch, and when the axis at e is in the same plane as the axis at e and the axis on whichthe cam rotates, no material vertical reciprocation is imparted to the member a and this is known as the neutral position. Provision is made to turn the control lever e to one'orother side as indicated by the brokenand full lines in Fig. 1 so that the feed and stitch may be reversed. The con-.

trol lever c has an operating arm 6 by which it maybe turned, thejouter part of the said arm being provided with a knob e having a stem screwed into the said arm.

The stem (2 is located in a slot betweenfprd.

jections e 6 having faces radially curved from the axis on which the control lever 0 turns so that the said lever may be secured in its adjusted position by screwing up the Carried by ment member 7 having an operative face f.

g is the aforesaid stop which is located and the stop 9. The saidlstop is so arranged that when the control lever e is in its neutral position the part of the abutment face directly opposite to it is that which is nearest to the axis of the controllever. Consequently when the stop 9 is in its innermost position the control lever cannot be moved materially from its neutral position and the said part of the abutment face may. be considered to be the neutral part, but according to the degree to which the said stop is located from the axis on which the control lever turns so the abutment member f and control lever may be turned to a position to either side of theneutral position and thus cause a corresponding rate of feed. When the stop is in its outermost position the control lever e may be turned to the maximum extent on one or other side of the neutral, that is, until the operative extremity of the abutment face on one or other side of the neutral part bears against the stop 9, thus permitting the highest rate of feed in one or other direction. According to the presentinvention, although the neutral part of the abutment face f is nearer to the axis on which the control lever e turns than the other operative parts of the said face the whole of the said face is on the outer side of an imaginary straight line, drawn between those operative parts of the abutment face most distant from the axis of the control lever, in other words the said abutment face is convex or outwardly angled. In the embodiment of the invention now being described, the said abutment face is convex as shown in Fig. 1 and curved to a similar extent and in a similar manner on each side of the neutral part which is therefore in the middle of the abutment face 7'". Consequently in this construction the control lever is stopped or its turning movement limited to the same distance on either side of the neutral position for any one position of the stop 9, otherwise of course, than in its innermost position when no material movement of the control lever c can take place. The stop 9 is conveniently adjusted in position by being provided with a helical groove g of about one convolution, and somewhat quick pitch in which is engaged, the inner end of the set screw 72/ working through the wall of the boss the said inner end being somewhat reduced in diameter. The said groove 9 has delinite limits corresponding to the desired limits of axial travel of the stop. The said set screw it when tightened up secures the stop f/ in position and when slightly relaxed, the inner end of the said screw acts as pin over which the helical groove works to cause axial movement of the stop when rotated. In order that the stop 9 may be conveniently rotated it is provided with a nick at its outer end. The outer end of the stop is also provided with an indicating pointer 15 and the outer face of the boss is marked with numerals to indicate the relative length of the stitch produced when the said pointer is in any particular angular position, which is dependent on the axial position of the stop g, to which it has been brought by rotation of it in one or other direction.

in Figs. 1 to 5 of the drawings, the stop is shown in its outermost position infull lines that is, the position admitting of the extremities of the abutment face 7" hearing against it, thus allowing the greatest rate of feed. y rotating the stop 9 in a clockwise direction, its inner end is moved inwardly, andthc construction is such that when the pointer 2' bears on the left hand side of the small stop j that is, when somewhat less than one complete rotation has been given to the stop it is in its innermost position, which is indicated by the broken lines in Fig. 1. The ends of the groove g also limit the movement of the stop in either direction.

The outer face of the boss 9 is shaped hel cally at a pitch equal to that of the helical groove and in the same direction so that the pointer may be close to the numerals on the face of the boss whatever he the position of the stop.

Instead of the abutment member 7 being carried by the control lever c it may be fixed and the stop 9 carried by the control lever. This construction and arrangement is illustrated in Fig. 6 in which the said step is slidably located within the operating arm 6 of the control lever which arm in this case is made tubular to accommodate the stop. The abutment member-f is secured by screws to the inner face of the bracket arm, or to a boss thereon. The axial movement of the stop 9 is controlled by a screw is the inner end of which engages in the helical groove. 9 in the stop but this screw is not used to secure the stop in its adjusted position. The stop 9 is provided with a stem on its outer end having a milled head g at its extremity by which the step may be rotated. The said stem passes through a tubular member 6 situated in the outer part of the operative arm 6 and against the outer end of this tubular memher a milled screw nut e engaged with a screw thread on the stem g may bear to lock the stop 9 in its adjusted position. The tubular member 6 is screw threaded on its outer side with which a milled screw nut Z engages so that the operative arm 6 may be secured in its adjusted position by turning the said nut up against the'faces e c.

Fig. 7 illustrates the embodiment of the invention in which the reciprocatory member is caused to reciprocate vertically by the embodiment of a pivoted slotted or grooved block as hereinbefore explained. on is the slotted or grooved block which is pivoted at m on a pin secured in the bracket arm, and n is a roller carried by the member a and engaging in the said block. By causing the block to assume an inclined position the lateral reeiprocations of the member a result in vertical reciprocations the extent of which depend upon the: amount of inclination given to the said block which when horizontal is in its neutral position. The said block m is provided with an operating 6 so as to turn with them.

member f is carried by the block m and arm tion, arrangement and action of the stop and abutment member are the same as in the construction shown in Figs. 1 to 5.

Instead of providing the stop with an indicating pointer and marking the face'of the boss with numerals for the purpose of on the stop, and a recess 39 is formed in the.

part of the boss 9' over the stop 9 of such a shape and in such position that any one numeral marked on the stop may be situated in the said recess for observation so that the operator may note what relative rate of feed the; position of thesaid stop will admit of In this arrangement the stop 9 is provided with a milled head forturning it. 7

Although it is preferred to form the abutment face 7"" slightly convex, yet it may be two slightly outwardly angled jplanef surfaces as illustrated diagrammatically in Fig. 9, but when an abutment face of such shape is employed, the distance between the innermost and outermost position of the stop 9 is greater than when the abutment face is convex so that to produce some particular variation in the rate of feed, greater longitudinal movement of the p has to begiven to i than when the abutment face is convex.

' Inthearrangements illustrated in Figs. 7. to 9, the abutment .face f is similarly shaped and disposed relatively to the axis on which the control member turns on each side of the neutral part of the said face, but this'is not essential as in some cases it may be desired, that whenever altering the position of thestop greater angular movement of the control member may be permitted upon one side of the neutral position than on the otherin any one position of the stop whereby on reversing the feed its'rate in one direction may be different in a certain de-' gree from the rate of feed in the other direction. Such a modification is diagrammatically illustrated in Fig. 10, in which the curve of the abutment face f is such that the lower part of the said face projects morethan the upper part from the axis on which' the control lever turns the result be-. ing that in any one position of the stop, the

control member may be turned more in. one

directionthan the other. This will be appreciated by examining Fig. 10 which indicates in full lines the BXtI'QIIIQPOSltlOIltOf the abutment member f on the lower side The construeof theneutral position and in broken lines its extreme positionabove the neutralpos1- tion which will be observed is nearer to.

the latter than the extreme position below, owing to the lower part of the-abutment face coming against the stooat a part of the said face nearer toits neutral part.

By forming the abutment face according to the said inventmn as herembefore described the axial path of movement of ad justment of the stop isvery shortwhereby the stop may be very rapidly adjusted even from one of its extreme positions to the other and enables the entire movement of the stop to be effected byless'than one rotation of it without the helical groove hav-.

ing an inconveniently quick pitch. It will be understood that the greater the convexity or the projection of the abutment face on the outer side ofan imaginary line between its two operative extremities the shorter is the path of axial adjustment movement of the stop.

What I claim and desire to secure by Letters Patent of the United Eltates, is

' l. Stitch regulating and reversing mecham rt rative extremities of said facev in o a to nnnniz'e the'necessary axial admet at O: .JllG stop toward and away from the abutment member.

Stitch regulating and reversing mechanism comprising an axially adjus able stop andan abutment member co-acti therewith, said stop and abutment member being relatively mova le the. position'which one may assume relative to the otherbeing de-'- termined by the axial adjustment of said stop, the operative face of the abutment member being convex in order to minimize thefnecessary axial adjustment of the, stop toward and away from the abutment mem-. ber.

3. Stitch regulating and reversing mechanism comprising an axially adjustable stop and an abutment member co-acting therewith, said stop and abutment mem ier being relatively movable, the position'which one may assume relative to the other being determined by the axial adjustment of said step, the operative face of the abutment member being outwardly angled in order to minimize the necessary axial adjustment of the stop toward and away from the abutmember (to-acting therewith, the operative face of the said member being oi: a projecting form on the outer side of an imaginary straight line between the operative extremities of the said face, and means for restricting the movement of said stop to less than a single revolution of movement, for the purpose set forth.

5. Stitch regulating and reversing mechanism comprising a stop and an abutment member co-acting therewith the operative face of the said member being convex and means For restricting the movement 01" said stop to less than a single revolution of movement.

6. Stitch regulating and reversing mechanism comprising a stop and an abutment member co-acting therewith the operative face of the said member being outwardly angled and means for restricting the movement of said stop to less than a single revolution of movement.

7. Stitch regulating and reversing mechanism comprising an axially adjustable stop and an abutment member co-acting there with the said stop having a helical groove formed therein corresponding in length to the movement which it is desired to impart to the stop the extreme ends of the groove being closed so as to arrest further movement of the stop in either direction, and a member projecting from the bearing for the said stop and engaging in the said groove to cause axial movement of the said stop when it is rotated.

8. Stitch regulating and reversing mechanism comprising an axially adjustable stop and an abutment member co-acting therewith the said stop having a helical groove which is less than a complete turn or convolution so as to correspond to the desired length of travel of the said stop and a member projecting from the bearing for the said stop and engaging in the said groove to cause axial movement of the said stop when it is rotated.

9. Stitch regulating and reversing mechanism comprising an axially adjustable stop and an abutment member co-acting therewith, the said stop having a helical groove in it, and a member projecting from the bearing for the said stop and engaging in the said groove to cause axial movement of the said stop when it is rotated, the ends of the said groove co-acting with the said member projecting from the stop bearing to limit the. axial movement of the said stop to its extreme operative positions in both directions.

10. Stitch regulating and reversing mechanism comprising an axially adjustable stop and an abutment member co-acting therewith the said stop having a helical groove a member projecting from the bearing for the said stop and engaging in the said groove, and a helical index having a pitch similar to that of the said helical groove.

11. Stitch regulating and reversing mechanism comprising an axially. adjustable stop and an abutment member, the said stop having a helical groove in which engages the inner end of a screw that acts both as a guide to cause axial movement of thestop when rotated and as a fixing for the stop when adjusted.

12. Stitch regulating and reversing mechanism, comprising in combination an axially adjustable stop and an abutment member co-acting therewith, the operative face of the said abutment being of a projecting form on the outer side of an imaginary straight line between the operative extremities of the said face, and the said stop having a helical groove in it of definite limits corresponding to the desired length of travel of the said stop and a member projecting from the bearing for the said stop and engaging in the said, groove.

13. Stitch regulating and reversing mechanism comprising an axially adjustable stop and an abutment member co-acting therewith the operative face of the said abutment member being on that side of an imaginary straight line between the two operative extremities of the said face, which is nearer to the said stop and the said stop having a helical groove, a member projecting from the bearing for the said stop and engaging in the said groove and a helical index having a pitch similar to that of the said helical groove.

14. Stitch regulating and reversing mechanism comprising an axially adjustable stop and an abutment member co-acting therewith having a convex operative face and the said stop having a helical groove of efinite limits corresponding to the desired. length of travel of the said stop and a member projecting from the bearing for the said stop and engaging in the said groove to cause axial movement of the said stop when the said stop is rotated, the ends'of the said groove limiting the said axial movement to the extreme operative positions of the stop in both directions. 7

.15. Stitch regulating and reversing mechanism comprising anaxiall adjustable stop and an abutment member co-acting therewith having an outwardly angled operative face and the said stop having a helical groove of definite limits corresponding to the desired length of travel of the said stop and a member projecting from the bearing for the said stop and engaging in the said. groove to cause axial movement of the said stop when the said stop is rotated, the ends of the said groove limiting the said axial movement to the extreme operative positions of the stop in both directions.

16. Stitch regulating and reversing mechanism comprising an axially adjustable stop,

an abutment member, said stop and abutment member being relatively movable, the

abutment member having a face with which said stop" member may contact to limit the relative movement between the stop and the abutment member the face of said abut- .ment memberbeing so shaped that when the stop 1s in contact with an lntermediate 7 point the abutment member and stop are held a ainst relative movement 1n either d1- b a I v I rectlon but relatlve movement 1n elther d1- adjustment of the stop a greater movement a is permitted between the stop-and tneabutment member at one side of sand 1nterm'e-' diate point than at the other side.

In testimony whereof I hereunto elk my signature.

CHARLES EDWARD FRANCIS. 

